Warp tension control means



April 6, 1954 Filed 001;. 23, 1948 R. H. ROUGHSEDGE ET AL WARP TENSIONCONTROL MEANS 3 Sheets-Sheet l INVENTORS. ROBE RT H.ROUGHSEDGE 1 April6, 954 R. H. ROUGHSEDGE ETAL 2,674,110

WARP TENSION CONTROL MEANS Filed Oct. 23, 1948 3 Sheets-Sheet 2 INVENTORS. ROBERT H.ROUGHSEDGE HANS G. LUSTIG ATTORNEYS.

WARP TENSION CONTROL MEANS 3 Sheets-Sheet 3 Filed Oct. 23, 1948INVENTORS. ROBERT H. ROUGHSEDGE @EQNS G. LUST 1G 1 I 4 A O Patented Apr.6, i954 WARP TENSION CONTROL MEANS Robert H. Roughsedge, Ramsey, N. J.,and Hans G. Lustig, New York, N. Y., assignors to Celanese Corporationof America, a corporation of Delaware Application October 23, 1948,Serial No. 56,172

13 Claims. (01'. 66-146) This invention relates to textile apparatus,and relates more particularly to warp tension control means and towarp-knitting machines in connection with which said warp tensioncontrol means are employed.

In the usual method of producing warp-knitted fabrics, that is, fabricsin which a number of warp threads are knitted together in each course; anumber of warp threads are drawn from any suitable source of supply suchas a warp beam or a number of sectional warp beams and are passed over awarp tension control means on their way to a knitting station. Thetension control means generally comprises a movable tension bar, overwhich the warp threads are trained, carried by one or more pivotallymounted arms. The tension bar is spring-loaded and as the tension on thewarp threads increases the tension bar moves in one direction stressingthe loading springs, and as the tension on the warp threads decreasesthe tension bar moves in the opposite direction under the urging of thesame springs. The movement of the tension bar is used to control therate of let-off of the warp threads from the warp beam or beams, therebyinsuring that the warp tension will not vary beyond a predeterminedrange.

In prior warp-knitting machines, helical springs were employed incompression to load the tension bar and it was found that the warptension varied excessively when the speed of the warp-knitting machineswas increased beyond a certain point, thus not only producing adefective fabric but also causing rapid wear of the machine parts. Theexcessive variation in warp tension apparently resulted from internaloscillations set up in the loading sprin s at high knitting speeds, andfrom the large effective inertia of springs employed in compressionwhich made it difficult for said springs to ad ust themselves to arapidly varyin warp tension. This limited the speed of the warp-knittingmachines to a maximum of about 400 to 500 courses per minute.

It is an important object of this invention to overcome the foregoingand other disadvantages of the warp-knitting machines hitherto employed,and to provide a warp-knitting machine capable of being operated atsubstantially higher knitting speeds.

A further object of this invention is to provide a warp tension controlmeans in which the material of the loading springs absorbs the stressesapplied to said springs in tensile and compressive strains.

Another object of this invention is to provide a warp tension controlmeans in which a spring is employed in torsion to load the tension bar.I

Other objects of this invention, together with certain details ofconstruction and combinations of parts, will be apparent from thefollowing detailed description and claims.

Our invention comprises a warp tension-control means in which theloading springs are em ployed in torsion rather than in compression ashas hitherto been customary. We have found that a warp-knitting machineincorporating this novel warp tension control means may'be op-' eratedat substantially higher knitting speeds ranging from 600 to '700 or morecourses per minute without excessive variation in the warp" tension.Even at these higher knitting'speeds; loading springs employed intorsion show no' tendency to develop internal oscillations and ex{ hibita lower effective inertia as compared with springs employed incompression. As a result, loading springs employed in torsion canaccommodate themselves readily to rapidly varying warp tension.

Springs employed in torsion and springs employed in compression differfrom each other in A tain improved results by employing the loadingsprings in other arrangements wherein the material in said loadingsprings absorbs the 'ap-" plied stresses in tensile and compressiverather than in torsional strains.

The number and the specific design of the load ing springs will dependin lar e part on the lay out of the warp tension control means and ofthe warp-knitting machine in which it is employed. However, in a warptension control means having'auxiliary loading sprin s between and inaddition to the main loading springs adjacent the ends of the tensionbar, it has been found that the best results are obtained when theauxiliary loading springs are employed in symmetrically positionedpairs, and each of said auxiliary loading springs has only one-half thestiffness of the main loading springs. in addition, if helically woundloading springs are employed, it is preferred that all of the loadingsprings be positioned in the warp tension con-' trol means so that theirdirection of winding alternates. While other arrangements with loadingsprings employed in torsion will give results superior to thoseobtainable with loading springs employed in compression, this particulararrangement permits the highest knitting speeds to be attained withoutan excessive variation in warp tension.

Various expedients may be employed to produce auxiliary loading springshaving one-half the stiffness of the main loading springs. For example,a spring wire of larger diameter maybe employed in the main loadingsprings, or the auxiliary loading springs may have twice as many turnsas the main loading springs-when a spring wire of the same diameter is.employed.

Means may be provided in the warp tension control means of thisinvention to vary the loading on the tension bar by altering thestresses applied to the loading springs. This permits of the adjustmentof the. warp tension for different types' and weights ofwarp threads,for different fabric constructions, or for any other purpose.

The motion of the-tension bar which results from ,the'variations in warptension may be-employedto control therate at which the-warp threads arelet oil from the'warp beam or-beams; For example; themotion'ofthetension bar may control a. positive let off of the. type shown intheFuhr-eretal. U. S. Patent No. 2,486,525, issued November-.1, 1949, toproduce-a warp-knitting. machine capable of operating at the highestknitting speeds. The motion of the tension bar mayalsocontrol othertypes of apparatus for regulating; therate-at which the warp threads811871813" off from the warp beam or beams such as brakesoperatingvonthe warp beam or beams, clutches through-which saidiwarp'beam or beamsare driven;- etc. in a manner well understood in the-art.-

Ihe warp tension: control means of this in.- vention is particularlyadapted for use withwarpknitting machines: ofall typesand-will bedescribed in connection therewith. Ittmay, however, alsoibe used withother typesof textile apparatusrin which-it is necessary to controlthewarp tension, such as slashers, for example. With such other typesof-apparatus the motion of the tension: bar may control the rate atwhich the warp-threads-are taken up aswell as the rate at, which theyare let off the warp-beam or beams.

A- preferred embodiment of our. invention is illustrated in theaccompanying drawings, .in which;

Fig; 1* is a front. elevational view, partly in section of-awarptensioncontrol means embodying; this invention 1011: one .bar of. .atwo-barwarp-knitting machine;, with the other bar omitted'intheinterestofclarity,

Fig; 2 is-a view, partly-in section, taken on line 2,-.-2of Fig. 1 in,thev direction ofthe arrows, with .certainparts omitted in the interestof clarity,

Eig.,3; is a:v-iew, partly-insection, taken generally on. line 3r 3=ofFig.1 1 in the direction of the. arrows, with certain-parts omitted inthe interest=ofclarity, and.

Fig. 4 isyadetail. view,,part1y in section and on, an'enlarged scale,taken on line 4-4 of Fig.- 3 imthe-direction of the arrows.-

Like reference numerals indicate like parts throughout vthe severalviews of the drawings.

Referring nowr-to .thedrawings-for a detailed description of, ourinvention there is shown a portion-era two-bar-warp-knittingmachine-comous machine elements.

prising a right-end main frame member H and an auxiliary frame memberl2. In addition to the frame members H and i2, the warp-knitting machinewill have a left-end main frame member and as many additional auxiliaryframe members as are needed to support the various machine elementsadequately. The left-end main frame member and the additional auxiliaryframe members have been omitted from the drawings in the interest ofclarity since they are identical in structure to the frame members H and12, respectively. It is to be understood that the auxiliary framemembers may be completely dispensed with when the warp-knitting machineis narrow enough so that the main frame members can provide adequatesupport for the vari- In Fig. 1 of the drawings, one of the two warptension control means which are needed in a two-bar warp-knittingmachine has been omitted since both are of identical structure.

The warp tension control means comprises a shaft l3 extending throughopenings M and 16 in' bosses Hand Win the frame members H and [2,respectively. At its-right end the shaft 13. is journa-lled' for freerotation in ball bearings I 9 and2l which are separated fromeach otherby means of an annular spacer 22. The ball bearing I9 is retained inposition by means of an annular disk 23 which is-fastened'to the. framemember H with screws 24 engaging threaded apertures 25 in the boss IT.The disk 23 is provided with a centrally-located aperture 21 throughwhich the shaft 13 extends. An' annular disk 28011 the other side of theframe member I I retains the ball bearing 2! in position, and like thedisk 23 is provided. with a centrally'located aperture 29 through whichthe shaft l3 extends. The disk 28. is also provided with an integralcircular bearing ring 3| extending into the opening' 1:4, which bearingring permits the disk 28 to be rotated without seizing or binding theshaft l3. The disk 28 is retained'in position by means of sleeves 32which abut the boss I! at one end and which are provided with enlargedcollars 33 spaced from said boss at their other end. The spacing betweentheboss i1 and the collars 33 somewhat greater than the thickness of thedisk28; permitting the disk to rotate freely about an axis extending inthe direction of the shaft [3. The sleeves 32 are fastened to the boss[1 bymeans of bolts 34 extending therethrough and engagingthreadedapertures 36 in said boss.

At thev auxiliary frame member 12, the shaft 13. is journalled for freerotation in a ball bearing 3.1 which is'seatedin the opening. Hi; Theball. bearing 31 is retained in position by means of two identicalannular disks 38' which are disposed: on each side of the auxiliaryframe memher [2. Eachofthe disks 38 is provided with a centrally locatedaperture39' through which the shaft" l3" extends and, like the disk 28,is also provided with an integralcircular bearing ring 4| extending intothe opening [6. The di'sks'38' are -heldin'positionby-means of sleeves42 which are fastened to the boss I8 with bolts 43 that extend throughsaid sleeves and engage threaded aper tures Minsaid' boss. Each ofthesleeves 42 abuts the boss l8 and'is provided with'an enlarged collar46, spaced from said boss, thespacing being somewhatgreater thanthethickness of the disks 38 .to permit said disks to rotatefreely'about an axis extending in the direction of the shaft i3.

A tubular tension bar 41 over which warp threads 48 are trained ispositioned in front of 5. and parallel to the shaft I3. At its right endthe tension bar extends through a sleeve 49 which is integral with oneend of main pivot arm The other end of the pivot arm 5| encircles theshaft I3 being fastened thereto by means of set screws 52. Adjacent tothe auxiliary frame member I2 the tension bar 41 extends through asleeve 53 which is fastened to a pair of auxiliary pivot arms 54positioned on each side of said auxiliary frame member. The pivot arms54 are in turn fastened to sleeves 56 which encircle the shaft I3 andare fastened thereto by means of set screws 51. As is shown in Fig. 2,each of the pivot arms 54 is cut away at 58 to clear the head of thebolts 43. The shaft I3 and the pivot arms 5| and 54 rotate as a unitduring operation permitting the tension bar 41 to move under theinfluence of changing warp tension.

The tension bar 41 is spring loaded by means of a main helical loadingspring 59 positioned adjacent to the main pivot arm 5|, and auxiliaryhelical loading springs 6| and 62 positioned adjacent to the auxiliarypivot arms 54. Each of the auxiliary loading springs 6| and 62 hassixteen turns, whereas the main loading spring 59 has only eight turnsso that the auxiliary loading springs 6| and 62 have only one-half thestiffness of the main loading spring 59. The exact number of turns inthe loading springs will depend upon the properties of the materialmaking up the springs and the design of the warp tension control meansand the warp-knitting machine in which said springs are employed. In allcases, however, each of the auxiliary loading springs 6| and 62 shouldhave only one-half the stiffness of the main loading spring 59. Both themain loading spring 59 and the auxiliary loading springs 6| and 62 arepreferably positioned in the warp tension control means with theirwindings disposed in alternately opposite directions. Thus, theauxiliary loading spring 8| has its winding disposed in a directionopposite to that of the main loading spring 59, the auxiliary loadingspring 62 has its winding disposed in a direction opposite to that ofauxiliary loading spring 6|, and so forth'to the left-end main loadingspring (not shown).

The main loading spring 59 is supported on an oil-impregnated bushing 63provided with shoulders 64, which bushing is mounted concentrically ofthe shaft I3. During operation, the bushing 63 provides a film oflubricant over the surface of the main loading spring 59 to reduce thefrictional forces thereon. One end 66 of the main loading spring 59 islooped around a sleeve 61 which is provided with a collar 68 that is cutaway at 69 to clear said spring. The sleeve 61 is fastened by means of abolt 1| extending therethrough to a lug 12 integral with a ring 13 whichencircles the shaft I3 and is fastened thereto with a set screw 14. Theother end 16 of the main loading spring 59 is looped around a sleeve 11(Fig. 4) provided with a shoulder 18 that is cut away at 19 to clearsaid spring. The sleeve 11 is fastened by means of a bolt 8| extendingtherethrough to a strap 82 which is in turn welded to the ring 28. Boththe main loading spring 59 and the bushing 83 are omitted from Figs. 3and 4 of the drawings in the interest of clarity.

The main loading spring 59 may be adjusted for a wide range of operatingconditions by means of an adjusting assembly indicated generally byreference numeral 83. The adjusting assembly 83 comprises" a'socket 84fastened to the frame member II in any desired manner, in which socket84, a rod, indicated generally by reference numeral 86, is secured bymeans of a bolt 81. The rod 86 has a straight section 88 connected toa;threaded section 89 of larger diameter by means of a taperedintermediate section 9|. A sleeve 92 fits loosely over the rod 86 andhas adjacent to its lower end a shoulder 93 which bears against thestrap 82. Adjusting nuts 94 and 96 in engagement with the threadedsection 89 of the rod 86 abut against the sleeve 92 permitting saidsleeve to be forced downwardly by rotation of said nuts. This in turnforces the strap 82 downwardly rotating the disk 28 and varying thetorsion in the main loading spring 59.

The auxiliary loading springs 6| and 62 are supported on oil-impregnatedbushings 91 provided with shoulders 98 which are mounted concentricallyof the shaft I3. Like the bushing 63, the bushings 91 provide a film oflubricant over the surfaces of the auxiliary loading springs 6| and 62to reduce the frictional forces thereon during operation. Ends 99 andI9I of the auxiliary loading springs 6| and 62, respectively, are loopedaround sleeves I82 which are provided with shoulders I83 that are cutaway at I84 to clear said springs. The sleeves I92 are fastened by meansof bolts I96 extending therethrough to lugs I91 integral with rings I88which encircle the shaft I3 and are fastened thereto with set screwsI89. The other ends III and H2 of the auxiliary loading springs 6| and62, respectively, are looped around sleeves II3 (Fig. 2)

* provided with shoulders II4 that are cut away at 6 to clear saidsprings. The sleeves I I3 are fastened by means of bolts 1 extendingtherethrough to straps II8 which are secured as by welding to the disks38 on each side of the auxiliary frame member I2. The straps II8 arefastened together to rotate as a unit by means of an end strap II 9 andbolts I2I. The auxiliary loading springs 6| and 62 and the bushings 91are omitted from Figure 2 of the drawings in the interest of clarity.

The auxiliary loading springs 6| and 62 may be simultaneously adjustedfor a wide range of operating conditions by means of an adjustingassembly, indicated generally by reference numeral I22. The adjustingassembly I22 comprises a socket I23 integral with the auxiliary framemember I 2, in which socket a rod, indicated generally by referencenumeral I24, is fastened by means of a bolt I26. The rod I24 is similarin construction to the rod 86 having a straight section I21, a taperedintermediate section I28, and a threaded section I 29 of larger diameterthan the straight section I21. A sleeve |3I fits loosely over the rod I24 and is provided with a shoulder I32 adjacent to its lower end whichbears against the straps II8. Adjusting nuts I33 and I34 in engagementwith the threaded section I29 of the rod I24 abut the sleeve IBIpermitting said sleeve to be. forced downwardly rotating the disks 38and simultaneously varying the torsion in both of the auxiliary loadingsprings 6| and 62.

During operation, the Warp threads 48 are trained over the tension bar41 on their way from the warp beam or beams to the knitting station. Asthe tension on the warp threads 48 increases the tension bar 41 will beforced downwardly rotating the shaft I3 in one direction and stressingthe loading springs 59, 69 and 6| in torsion. Conversely, as the tensionon the warp threads 48 decreases the shaft l3- will be rotated-finthe-"oppo= site direction'un'der the urging of the stressed loadingsprings 59, 61 and 62th'ereby raising the tension bar- 41. The rotationof the shaft l3 and/or'the motion of the tension bar'fl may, as pointedout above, be employed to control the let off of the war threads 48 fromthe warp beam or beams. The spring loading upon the tension bar GI maybe readily varied by means of the adjusting nuts 94, 9B, 33 and 134 fordifferent types of warp threads 48, for different fabric constructions,or forany other purpose.

It is to be understood that the foregoing detailed descriptionis givenmerely by way of illustration and that many variations may be madetherein without departing from" the spirit of our invention.

Having described our invention, what we desire to secure'by LettersPatent is:

1. In a warp tension control means, a movable tension bar" over whichthe warp threads are trained, main spring loading means operativelyconnected to said tension bar" adjacent the ends of said tension bar,and auxiliaryspring' loading means operatively connected-to said tensionbar intermediate saidmain" spring loading means, each of said mainspring loading means comprisi'ng a single-loading spring, and each of'said auxiliary spring loadingmeans comprising a pair of loadingsprings;

2. Inawarp' tension control means, a movable tension bar over which thewarp threads are trained, spring loading means absorbing the stressesappliedthereto in tensile and compressive strains operatively connectedto said ten sion bar adjacent the ends of said tension bar; andauxiliary spring loading means absorbing the stresses a pued thereto intensile and compressive strains ope'ratively connectedto said tensionbar intermediate said main spring loading means, each of said mainspring" loading means comprisin a single-loading spring; and each ofsaid auxiliary spring loading means" comprising a pair of loadingsprings.

3. In a warp tension control'means, a movable tension bar over which thewarp threads are trained, and a plurality of spring loading meansabsorbing the stresses applied thereto in tensile andcoinpressives'trains; saidspring-means having one end fixed and theotherend operatively connected to said tension bar, the springs in saidspring loading means having windings disposed in alternately oppositedirections.

4; In a warptension control means, a movable tension bar over which thewarp threads are trained, main spring loading means employed in torsionoperatively connected to said tension bar adjacent the'ends of saidtension bar, and auxili ary spring loading means employed in torsionoperatively connected to said tension bar-intermediate said main springloading means, each of said main spring loading means comprising asingle-loading spring, each of said auxiliary spring loading meanscomprising a pair of loading springs and all of said loading springshaving windingsdisposed in alternately opposite directions.

5. In a warp tension control means, a movable tensionbar over which thewarp threads are trained, main spring loading means operativelyconnected to-saidtension bar adjacent the ends of said tension bar, andauxiliary spring loading means operatively connected to said tension barintermediate said main spring loading means,

each ofsaidmain spring loading meanscompris- 8., ing a'- single" loadingspring, each of said auxiliary spring loading means comprisinga pair ofloadirig springs, and each of the loading springs in said auxiliaryspringloading means having one half the stiffness of the loading springsin said main spring loading means.

6. In a warp tension control means, a movable tension bar over which thewarp threads are trained, main spring loading means absorbing thestresses applied'thereto in tensile and compressive strains operativelyconnected to said tension bar adjacent the ends of said tension bar, andauxiliary spring loading means absorbing the stresses applied thereto intensile and compressive strains operatively connected to said tensionbar intermediate saidmain spring loading means, each of said mainspringloading means compris irig a single'loading spring, each of saidauxiliary spring loading means comprising a pair of loading springs, andeach of the loading springs in said auxiliary springloading means havingone half the stiffness of the loading springs in said main springloading means.

7. In a warp tension control means, a tension bar over which the warpthreads are trained, main arms adjacent the ends of the tension bar forpivotally'supporting the tension bar, auxiliary arms intermediate themain supporting arms for pivot'ally supporting the tension bar, ahelical spring employed in torsion adjacent each of the main supportingarms for loading the tension bar, and pairs of helical springs employedin torsion positioned on each side of the auxiliary supporting arms forloading the tension bar.

8. In a warp tension control means, a pair of main frame members,auxiliary frame members intermediate saidmain frame members, a tensionbar over which the warpthreads are trained, main arms adjacentthe'mairi'frame' member for pivotally supporting the ends of the tensionbar, auxiliary arms intermedi'ate the main supporting arms and adjacentthe auxiliary frame member for pivotally supporting the tension bar, ahelical spring employed in torsion adjacent each of the main supportingarms for loading the'ten sionbar, and pairs of helical springs employedin torsion positioned on each side of the auxiliary supporting arms forloading the tension bar,one ehd of each of said loadingsprings beingoperatively fastened to the supporting arm adjacent thereto, an'dtheother end of each of said load' ing' springs being adjustably fastenedto the frame member adjacent thereto.

9. In a warp tensicncontrol means, a pairof main frame members,auxiliary frame members intermediate'said main frame members, arotatable shaft mounted between said frame members, a tubular tensionbar over which the warp threads are trained positioned in-front of andparallel to said shaft, main arms fastened to said shaft adjacent themain-frame members for pivotally supportingthe tension bar, auxiliaryarms fastened to said shaft on each side of the auxiliary'frame membersfor pivotally supporting'the tension bar, a helical spring employed intorsion encircling the shaft adjacent each of the main frame membersforloading said tension bar, said springhaving one'end fastened to saidshaftand the other end adjustably fastened to the main frame memberadjacent thereto, pairs of helical springs employed in torsionencircling the shaft on each side'of th'e auxiliary frame members forloading said tension bar, said springs having one end fastened to saidshaft and theother end ad-' justablyfastened to the auxiliary'framemember,

each of the loading springs adjacent said auxiliary frame members havingtwice as many turns as the loadin springs positioned adjacent the mainframe member, all of the loading springs having their windings disposedin alternately opposite directions, and oil-impregnated bushings mountedon said shaft internally of each of the loading springs for lubricatingthe loading springs.

10. In a warp tension control means, a movable tension bar over whichthe warp threads are trained, main spring loading mean operativelyconnected to said tension bar, and auxiliary spring loading meansoperatively connected to said tension bar, each of said main spring loading means comprising a single loading spring, and each of said auxiliaryspring loading means comprising a pair of loading springs.

11. In a warp tension control means, a rotatable shaft, spaced armsmounted on said shaft, a tension bar over which the warp threads aretrained carried by said arms, and a helical spring encircling said shafthaving one end fixed and the other end operatively connected to saidshaft for loading said tension bar whereby the motion of the tension barwill ap ly a torsional stress to said spring.

12. In a warp tension control means, a rotatable shaft, supporting meansfixed to said shaft, a tension bar over which the Warp threads aretrained carried by said supporting means, a helical spring encirclingsaid shaft having one end operatively connected to said shaft forloading said tension bar whereby the motion of the tension bar willapply a torsional stress to said spring, a. member engagin the other endof said spring and screw means for moving said memoer for adjusting theloading of the tension bar.

13. In a warp tension control means, a rotatable shaft, supporting meansfixed to said a a tension bar over which the warp threads are trainedcarried by said supporting means, a plurality of helical springsencircling said shaft and having their windings disposed in alternatelyopposite directions, each helical spring having one end fixed and theother end operatively comiected to said shaft for loading said tensionbar whereby the motion of the tension bar will apply a torsional stressto said springs, and screw means for shifting the relative position ofthe ends of the spring for adjusting the loading of the tension bar.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 410,505 Eck Sept. 3, 1889 671,534 Bartlett Apr. 9, 1901745,240 Rolland Nov. 24, 1903 745,449 Mayo Dec. 1, 1903 1,790,201 DavisJan. 27, 1931 2,308,430 Bolden Jan. 12, 1943 2,327,747 Sirmay Aug. 24,1943 2,448,035 Lambach Aug. 31, 1948

